CONNECTION ABNORMALITY DETECTION METHOD, NETWORK SYSTEM, AND MASTER DEVICE

摘要

There is provided a technique for detecting a connection abnormality of a slave device, in a network system including a master device and slave devices. A connection abnormality detection method of the present invention is a connection abnormality detection method in a network system including a master device and a plurality of slave devices. In the network system, data is transmitted from the master device and then is returned to the master device through the respective slave devices. Each slave device has an upstream-side port and a downstream-side port. The connection abnormality detection method includes a step of acquiring topology information of the network system, a step of closing or opening the port of each slave device such that a serial topology is formed to include a target slave device located on the downmost stream side, a step of transmitting inspection data after the control of the port, and a step of detecting a connection abnormality of the device on the basis of a status of return of the inspection data.